Stock bar guide feed tube



April 19, 1960 F. D. LAKINS STOCK BAR GUIDE FEED TUBE Filed Aug. 22, 1957 INVENTOR. FraDKNhQLQK/h: BY 2 ATT SRNE).

United States Patent STGCK BAR GUIDE FEED TUBE Franklin D. Laldns, Nedrow,.l-l.Y., assignor to Lipe- Rollway Corporation, Syracuse, Niifl, a corporation of New York Application August 22, 1957, Serial No. 679,690

4 Claims. c1. ma as This invention relates to stock bar feeding tubes, or guides, of the type used in connection with automatic bar working machines wherein the stock bar is fed through the tube and into the bar working machine. The feed tubes, or guides, are formed of metal and usually, the stock bars are of metal and are several feet in length when initially placed into the bar feed guide. The bars are rotated within the guide tube at high speed during the formation of the work piece. This high speed rotation of the long bar sets up undulations in the bar whereby the bar vibrates violently against the inside of the tube, creating an undesirable noise of considerable magnitude, well exceeding one hundred decibels.

Heretofore, various attempts have been made to construct feed tubes in such a manner as to reduce the noise below an undesirable level. However these attempts, while adding materially to the cost of the feed tubes, have not resulted in any appreciable reduction of the noise level.

This invention has as an object a stock bar feed tube embodying a structural arrangement which is particularly economical to manufacture and which functions to reduce the noise level so that it is not objectionable.

The invention consists in the novel features and in the combinations and constructions hereinafter set forth and claimed.

In describing this invention, reference is had to the accompanying drawings in which like characters designate corresponding parts in all the views.

In the drawings- Figure 1 is a cross sectional view of a stock bar feed tube embodying my invention, and

Figure 2 is a foreshortened longitudinal cross sectional view of the feed tube.

The stock bar feed tube here illustrated is of the general type disclosed in Patent No. 2,300,457, issued to E. S. Mariotte, November 3, 1942.

Referring to the drawings, the feed tube consists of an inner member 10 positioned within and in spaced concentric relation to an outer member 12. The inner and outer members are shown in the form of metal tubes fixedly secured together at their ends by annular end wall members 14, the tubes being affixed to the end members 14, as by being welded thereto, whereby the space between the inner and outer members forms a closed compartment.

The outer tube 12 is formed adjacent each end thereof with threaded apertures 25, 26, provided with closure 2,933,173 Patented Apr. 19, 1960 plugs 27, 28. The space between the inner and outer tubes 12 is filled with a viscous material 22 of a putty-like nature-that is, a material consisting essentially of a mixture of metallic salts and oil. For example, ordinary putty or caulking compound comprising calcium carbonate and linseed oil with, or without, a. percentage of lead carbonate. The composition is blended to a viscous texture which will flow under pressure and is introduced into the space between the tubes 10, 12, by suitable pressure applying apparatus.

The plugs 27, 28, are removed and the viscous composition is forced through one of the apertures, as the aperture 25. The composition is forced into the space between the inner and outer tubes until it exudes from the opening 26 at the opposite end of the tube, whereupon the plugs 27, 28, are threaded into the apertures to close the compartment. In this manner, the entire space is filled. with the composition. in practice, it has been found that the composition can be properly introduced in the space between the inner and outer tubes under pressure of approximately ninety pounds per square inch. This composition serves as a particularly efiicient sound dampening or insulating medium whereby the vibrations imparted to the inner tube lit by rotating stock bar are materially dampened before reaching the outer tube 12. With this arrangement, the noise level is reduced twenty or more decibels.

What I claim is:

l. A stock bar feed tube comprising an elongated inner imperforate metallic member, an outer member of length comparable to said inner member, said members being fixedly joined together to provide a closed space between said members, said space extending substantially comparable to the length of said inner and outer members and being filled with a viscous putty-like composition.

2. A stock bar feed tube, as set forth in claim 1, wherein the space between said inner and outer members is filled with a sound absorbent medium consisting essentially of a putty-like material.

3. A stock bar feed tube, as set forth in claim 1, wherein the space between said inner and ter members is filled with a composition consisting essentially of a mixture of metallic salts and linseed oil.

4. A stock bar feed tube comprising inner and outer imperforate tubular members of comparable length arranged in spaced concentric relation, said tubes being fixedly joined at their ends to provide a closed compartment between said inner and outer tubes, said compartment beingcompletely filled with a sound absorbent material consisting essentially of a mixture of metallic salts and linseed oil.

References Cited in the file of this patent UNITED STATES PATENTS 903,878 Mock Nov. 17, 1908 1,891,290 Tessky Dec. 20, 1932 2,133,376 Brown Oct. 18, 1938 2,419,278 Motsenbocker Apr. 22, 1947 FOREIGN PATENTS 214,957 Witzerland Oct. 1, 1941 

